The present invention relates generally to highly sensitive biological sensors, to a method for the detection of biological agents using such sensors, to a polymer system for use in such sensors, and to chemical moieties for inclusion in such polymer systems.
The desirable properties of conjugated polymers depend on their intense fluorescence and highly delocalized photophysical properties. These properties are important for a variety of applications ranging from LED to a recently demonstrated biosensing application (WO 00/66790) to manipulate the fluorescence quantum efficiency (QE) and control both the wavelength and excited state decay channels present in the conjugated polymer. In previous studies it was discovered that the fluorescence QE of an ionic conjugated polymer can be increased through interacting with small amount of certain detergents (Chem. Phys. Lett., v. 330(#1-2) pp.27-33, Nov. 3, 2000). It was believed that the surfactant can inhibit the folding of the polymer chains, reduce the conformational disorder and thus increase the QE.
In WO 00/66790, a conjugated polymer base biosensor was developed, in which the signal transduction came from the reversal of quenched polymer fluorescence by a quencher-ligand diad. While that biosensor system is quite: successful in detecting various of toxins and viruses, one drawback is the non-specific interactions between the ionic conjugated polymer and proteins, which can also cause a change in the fluorescence of the conjugated polymer. The interactions of polyelectrolytes with proteins are well known processes, which actually have drawn lots of attention in the literature due to importance of such interactions in natural biological systems as well as biotechnological applications.
In accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention includes a chemical moiety comprising the reaction product of (i) a polyelectrolyte monomer and (ii) a biological agent recognition element-substituted polyelectrolyte monomer.
The present invention also includes a polymer system including an ionic conjugated polymer, and, an electronically inert polyelectrolyte having a biological agent recognition element bound thereto.
The present invention also includes method of detecting a biological agent including contacting a sample with a sensor including a polymer system capable of having an alterable measurable property selected from the group consisting of luminescence, anisotropy, redox potential and uv/vis absorption, said polymer system including an ionic conjugated polymer and an electronically inert polyelectrolyte having a biological agent recognition element bound thereto, said electronically inert polyelectrolyte adapted for undergoing a conformational structural change upon exposure to a biological agent having affinity for binding to said recognition element bound to said electronically inert polyelectrolyte, and, detecting said detectable change in said alterable measurable property.
The present invention also includes sensor including a polymer system capable of having an alterable measurable property selected from the group consisting of luminescence, anisotropy, redox potential and uv/vis absorption, said polymer system including an ionic conjugated polymer and an electronically inert polyelectrolyte having a biological agent recognition element bound thereto, said electronically inert polyelectrolyte adapted for undergoing a conformational structural change upon exposure to a biological agent having affinity for binding to said recognition element bound to said electronically inert polyelectrolyte whereby a detectable change in said alterable measurable property can occur, and, a means of detecting said detectable change in said alterable measurable property.
The present invention also includes a process of tuning the properties of an ionic conjugated polymer including admixing an ionic conjugated polymer with an electronically inert polyelectrolyte comprising the reaction product of (i) a polyelectrolyte monomer and (ii) a biological, agent recognition element-substituted polyelectrolyte monomer.
The present invention also includes a kit for the detection of biological agents including a fluorescent polymer, and, an electronically inert polyelectrolyte having a biological agent recognition element bound thereto.